The development of mobile communication devices starting with smartphones and user terminal devices, and the high distribution rate of smartphones, have enabled users to easily acquire and exchange information even in everyday lives.
In order to extend functions and performances supported by user terminal devices and enable users to further easily and familiarly use various functions provided from the user terminal devices, efforts to develop active user interfaces (UIs) and interactive user experiences (UXs) of the user terminal devices have been made.
An existing user terminal device has used a voice recognition technology of a user as a unit for inputting a command for executing functions installed in the user terminal device. In this case, the voice recognition technology is used as a method of converting a natural language (a voice) of a person into a computer language recognizable by a machine to generate a command, and transmitting the command to a function module simply supported by the user terminal device.
However, since the natural language has an ambiguous meaning or a homonym, it is difficult to form a command intended by a user by using only information simply converted from a voice into a text.
In addition, since a user carries and uses a mobile user terminal device, a distorted command is transmitted or wrong information is acquired due to an effect of a surrounding environment such as noise or the like.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.